Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2011-06-15

Journal: JOURNAL OF NUCLEAR MATERIALS

Included Journals: EI、SCIE

Volume: 413

Issue: 2

Page Number: 90-94

ISSN: 0022-3115

Abstract: The stability and migration behavior of helium and self defects in vanadium and V-4Cr-4Ti alloy are studied by first-principles calculations. The tetrahedral site is found as the most stable configuration for interstitial He, followed by the octahedral and substitutional sites. Among the self defects, the mono-vacancy has lower formation energy (1.71 eV for V and 2.14 eV for V-4Cr-4Ti alloy) than the self interstitial ones. The migration energies for He hopping between the tetrahedral sites are 0.06 and 0.09 eV for vanadium and V-4Cr-4Ti alloy, respectively. Our calculations reveal strong repulsion between two interstitial He atoms and strong attraction between He and vacancy, suggesting that vacancy acts as a trapping site for He impurity and a seed for further bubble formation. (C) 2011 Elsevier B.V. All rights reserved.